The object of the present invention is a method for the production of furan resins, useful for the preparation of binder systems comprising such resins in admixture with silica sand, or other granular substances, for the production of foundry cores and molds, or for the production of refractory bricks or refractory masses aimed to the metallurgical or glassmaking industry. The furan resins obtainable by the method of the invention are characterized by a low free formaldehyde content, which entails the advantage of reduced formaldehyde emissions under the conditions of use of the resins in the foundry.
Further objects of the present invention are, therefore, the furan resins obtainable by the method of the invention, their use in the production of foundry binder mixtures, preferably for no-bake foundry binder mixtures, the foundry binder mixtures comprising the furan resins obtainable by the method of the invention, the foundry binder systems comprising the foundry binder mixtures mentioned above, the foundry cores and/or molds comprising the foundry binder mixtures mentioned above, the process for the production of said foundry cores and/or molds and the foundry cores and/or molds obtainable by said process.